The effects of sewage sludge doses on the root system of peach palm were studied in a field experiment, in randomized complete blocks, carried out in Ubatuba, state of São Paulo, Brazil. The trial was set up in July 2001, with a density of 5,000 plants ha-1. The sewage sludge doses (79.7 % water content) were 0, 38, 76, and 152 t ha-1, which were equivalent to doses of 0, 100, 200, and 400 kg ha-1 of N. The treatments were applied in the planting furrow, and every plant was provided with K by a dose of 15 g potassium chloride. The root system was analyzed one year after planting using soil auger and digging of trenches and with the help of digital images. It was concluded that the root system of one-year old peach palm was concentrated in the upper soil layer (over 75 % in the 0-20 cm surface layer), and within a horizontal distance of 0.50 m from the palm trunk. The sewage sludge positively modified the soil density as well as the root density. There was an increment in root biomass proportional to the sludge doses, and there was a positive linear relationship between the root and shoot biomass. Sludge doses equivalent to 200 and 400 kg ha-1 of N allowed the root system to explore deeper soil layers, as well as the development of more fine roots compared to the other treatments.
Bactris gasipaes; Bactris gasipaes; biosolid; heart-of-palm; pejibaye; root density
